Max the 401(k) and an IRA first.

The trick to saving and not succumbing to lifestyle creep is to automate saving. Open a taxable brokerage account and put part of your pay in it. My employer uses ADP and I have a Schwab brokerage account. Schwab gives your account a standard ABA routing number and account number, and I have it set up in my ADP portal to direct deposit a fixed amount into the brokerage account every payday, and the "remainder" deposited to my everyday bank account. It's amazing how quickly it adds up.

If you don't have a good emergency fund, use the brokerage to start building one. Invest in T-Bill ladders and a money market fund like SWVXX until you have six month's living expenses. After you have that much in your e-fund, start investing in a total market ETF like SCHB.